Alice Park

Alice Park

Alice Park is a staff writer at TIME. Since 1993, she has reported on the breaking frontiers of health and medicine in articles covering issues such as AIDS, anxiety and Alzheimer's disease. Her latest book is The Stem Cell Hope: How Stem Cell Medicine Can Change Our Lives.

The Weird Benefit of Eating Salty Food

Too much salt can lead to heart disease, but there may be a healthy side to salt that hasn’t been appreciated — until now

If you’re an average American, chances are that you’re eating too much salt. But the latest research — which, the scientists stress, is still in its early stages — hints that there may be some benefits to salt that have gone unnoticed. Salt, it seems, may be an ancient way for the body to protect itself against bacteria.

Reporting in the journalCell Metabolism, Jonathan Jantsch, from the University of Regensburg in Germany, says that salt may be an effective way to ward off microbes. In a series of studies using both mice and human cells, he and his colleagues found that levels of sodium go up around an infection site, and that without salt, bacteria tend to flourish and grow better.

The discovery came about by accident, after Jens Titze, the study’s senior author, noticed that mice who had been bitten by their cage mates showed higher levels of sodium in their skin than those who were wound-free. Jantsch decided to find out whether the salt had something to do with the infection-fighting functions of the immune system.

He and his team conducted a series of experiments in which they subjected mouse and human cells to high levels of sodium chloride, and watched the immune cells activate. They also fed mice diets that were low and high in sodium, and then infected them with Leishmania major. The mice fed the higher amounts of sodium showed stronger immune responses to the wounds, and cleared their infections faster than the mice eating less salt. In fact, Jantsch speculates that certain skin cells may transport sodium preferentially to sites where bacterial populations are high in order to create another barrier preventing the microbes from entering deeper into the body.

That opens the possibility that salt may be an unrecognized contributor to the immune system, and possibly a remnant from the days before antibiotics, when mammals, including humans, needed some allies in the fight against microbes. After all, salt has been used for centuries to preserve food from spoiling in bacteria’s presence, so it makes sense that evolutionarily, sodium might have also been co-opted by the body in a similar way. “I really think salt is an unappreciated factor of immunity,” says Jantsch.

If that’s the case, then it may be possible to take advantage of salt-based dressings, for instance, to improve wound healing. Burn patients may benefit the most, since their skin, the first line of defense against microbes, is compromised. And for those with hyperactive immune responses, dialing down the concentration of sodium at specific areas might also be helpful. “We are interested in how this works, because it can have broad applications,” says Jantsch. “We can possibly target and boost sodium in situations where we need more salt if it’s deficient, and lower it in situations where there is salt overload and hypertension.” Already, some companies have produced wound dressings with enhanced sodium concentration as a way to help infections heal faster.

He stresses, however, that the results don’t mean high salt diets are now healthy — or advisable. His studies, even in mice, haven’t worked out exactly how salt in the diet affects the body’s ability to recruit the nutrient to fight infections. And to get the bacteria-fighting effect, the mice were fed a diet that was extremely high in sodium — 4%, compared to the average mouse chow which is only 0.2% to 0.3% sodium. “There is overwhelming data that tells you a high salt diet is detrimental to the heart,” he says. “We used one animal approach to look at the beneficial role of salt. So I would be hesitant to draw any conclusions for humans at this stage.” He and others are already setting up more experiments, however, to study how salt might become the next weapon in fighting infections.

Alzheimer’s Protein Found in Young Brains for the First Time

The brain-damaging protein in Alzheimer’s disease may start accumulating as early as in our 20s

For the first time, scientists have found evidence of a protein found in Alzheimer’s disease, called amyloid, in the brains of people as young as 20.

In a report published in the journal Brain, Changiz Geula, a professor at the Cognitive Neurology and Alzheimer’s Disease Center at Northwestern University Feinberg School of Medicine, reveals that the protein—which gradually builds up and forms sticky plaques in the brain in Alzheimer’s disease—starts appearing early in life. Amyloid is normally made by the brain and has important functions; it’s an antioxidant and promotes the brain’s ability to remain adaptable by forming new connections and reinforcing old ones, especially those involving memory. But in some people, the proteins start to clump together with age, forming sticky masses that interfere with normal nerve function. Eventually, these masses kill neurons by starving them of their critical nutrients and their ability to communicate with other cells.

When Geula compared the autopsy brains from normal people between ages 20-66 years, older people without dementia between 70-99 years, and people with Alzheimer’s between 60-95 years, they found evidence of amyloid in a particular part of the brain in all of them. That region isn’t normally studied in Alzheimer’s, but it plays roles in memory and attention.

The results show that the process responsible for causing Alzheimer’s begins as early as in the 20s, and it also pointed to a population of cells that are especially vulnerable to accumulating amyloid—essentially serving as a harbinger of future disease. “There is some characteristic of these neurons that allows amyloid to accumulate there more than in other neurons,” says Geula. “At least in this cell population, the machinery to form aggregates is there.” Reducing the amount of amyloid in the brains of young people might help halt the formation of Alzheimer’s, he says.

Because the study involved autopsy specimens, there’s no way to tell whether those younger individuals would have gone on to develop Alzheimer’s. But they provide a clue about the early steps behind the disease.

They may also shed light on one way to prevent, or at least minimize, the effects of Alzheimer’s. Experts currently believe that the memory-robbing condition occurs when the balance between the production of amyloid and processes that clear the protein from the brain veer out of balance with age. As more amyloid is left in the brain, it tends to become stickier and adhere to other amyloid fragments, eventually forming damaging plaques. Geula believes that even in people with a genetic predisposition to forming these sticky plaques, removing amyloid as early as possible can slow down the progression of the disease. While there aren’t any effective ways to do this yet, there are promising compounds currently being tested in clinical trials. And given Geula’s findings, those studies become even more critical as a way to help more people to treat and even prevent the disease.

Many Doctors Give In When Parents Want to Space Out Vaccines

The vast majority of doctors don’t believe that spacing out childhood immunizations is a good idea, but they’re doing it anyway. Here’s why

It’s an eye-opening survey, to say the least, and its findings are clear: Nearly all — 93% — primary care doctors and pediatricians surveyed say that in a typical month, parents ask them to deviate from the recommended childhood immunization schedule and instead give the shots over a longer period of time, according to a report published Monday in the journal Pediatrics. And while nearly 90% thought that such spacing out of the immunizations would put the children, and the community at risk of spreading infectious diseases like measles, 37% said they agreed to do so often or always. That was a 131% increase since the last survey, conducted in 2009, when only 16% said they agreed to changing the recommended vaccine schedule.

“Doctors are feeling really conflicted because they overwhelmingly think this is the wrong thing to do, and is putting children at risk, but at the same time, they want to build trust with their patients and meet people halfway,” says Dr. Allison Kempe, professor of pediatrics at University of Colorado and Children’s Hospital Colorado, who is the lead author of the study.

Even more concerning, she says, is the fact that 40% of the physicians said that the vaccine issue was the source of their job dissatisfaction. The survey also asked them about different strategies the doctors employed with parents to discuss the importance of following the existing vaccination schedule, but the doctors revealed very little confidence in those methods. In fact, the strategy they believed worked most often only garnered a 20% effectiveness rating, and that was telling parents that the doctors immunized their own children according to the recommended schedule.

“It’s a terrible conflict when I have to make a decision when I’m doing my vaccine orders for a particular child and decide if it’s going to be the pertussis vaccine for that infant or the Hib or the pneumococcal,” says Dr. Julie Boom, director of the immunization project at Texas Children’s Hospital and associate professor of pediatrics at Baylor College of Medicine, of the decision she has to make when parents insist on giving their babies only one immunization during a visit. While Boom makes every effort to discuss with parents the importance of sticking with the recommended immunization schedule, she says “I will offer the vaccine at that visit and explain the risks and benefits of the decision that parent is making and try to get them to come back as quickly as possible to take the next vaccine so the baby will be fully vaccinated as on time as possible.”

But she does that knowing that the baby leaves her office at higher risk of potentially getting sick since he is not fully immunized. “The baby leaving my office is at risk of getting the illnesses for which he’s not vaccinated,” she says. “To know I’m going to pick one [vaccine] and leave the other behind, despite all the time I spend explaining the risks and benefits to the parents—it’s very difficult for me.”

And it’s increasingly a problem for her colleagues as well. While parents who refused to vaccinate their children gained the most media attention in recent years and likely contributed to pertussis and measles outbreaks, even more parents – about 13% — used an alternative vaccine schedule that included delaying some of the shots. These parents often express concern about “overloading” their babies’ immune systems with too many shots in one visit (the most that infants generally get are five, at the year-old visit). In the survey, 35% of doctors said they realized that allowing parents to delay shots sent mixed messages; parents could interpret the action as proof that the existing schedule wasn’t so important after all if doctors ended up changing it.

Part of the conflict may come from the advice from organizations to which these physicians turn for help. As some frustrated doctors began to “fire” their patients and refuse to see them if they declined to vaccinate their children or asked for alternative immunization schedules, in 2005, the American Academy of Pediatrics advised its members to not dismiss those parents and urged them to discuss and educate them instead about the importance of vaccinations and of getting them on time. That may explain why 82% of doctors in the current survey said they felt agreeing to delaying some vaccines would build trust with their patients; 80% said that if they refused to accommodate the parents wishes, these parents would leave to find some doctors who would.

“Nobody is in favor of dismissing patients, but I think we need to get a little bit straighter about communicating to these parents about how strongly we feel about vaccinations, and how detrimental spacing them out is for their child,” says Kempe.

Among the most commonly used strategies to convince parents, doctors cited their comfort with vaccinating their own children according to the schedule, stressing that spacing out vaccines puts their children at risk of getting sick, reminding them of recent outbreaks of vaccine-preventable diseases, and explaining that alternative schedule haven’t been studied for their safety. Doctors have even informed parents that bringing their child back for multiple visits to get jabbed with a shot can be more painful for the baby. None were rated by the physicians as being more than 20% effective, leaving doctors at a loss.

That’s why professional organizations should take a stronger role in providing doctors with more guidance about what may work and what doesn’t. Conducting more studies on different methods of educating and addressing parents concerns could arm doctors with more data and scientific evidence to back up their belief in the established immunization schedule, for example. Kempe also notes that starting to educate parents earlier, such as during pregnancy, may help to reinforce their comfort with vaccines and what they can do to protect their baby once he is born. And reaching parents and parents-to-be on a more consistent basis may also be key to alleviating their concerns about vaccines. “We as doctors have not exploited mass media or the kinds of media that the anti-vaccine movement has,” says Kempe. “We are not doing a great job of countering the misinformation out there, and also not doing a good job of enlisting parents who are pro-vaccine in a proactive way to establish a social norm.”

Part of that has to do with the fact that the time that doctors typically have with parents during well-baby visits is short. Most doctors reported having to spend at least 10 minutes with parents to address their vaccine concerns; that’s about half of the time of an average visit, which also has to cover other important wellness issues such as nutrition, car safety, and more. So Kempe says other strategies, such as group visits or sessions to address vaccine questions specifically, or designated staff at family practices or pediatricians’ offices who are assigned the task of answering questions about vaccines and vaccine safety might be more effective. In Boom’s practice, she often schedules a separate visit for parents to discuss just their vaccine questions, so she doesn’t feel rushed to come to a decision about whether to help the parents space out vaccines or not.

For Boom, the key is understanding where the parents’ concerns come from. “For one parent it may be about long term effects of vaccinations, and for another it may be something else,” she says. “You have to understand where the misinformation is coming from, and then very specifically address each parent’s questions. It does take time.”

Using this strategy, Boom feels she is relatively successful in educating parents about the need to follow the recommended vaccination schedule. But she admits that working in an academic institution, she has the luxury or more time with her patients.

For those that don’t, it’s clear that frustration is reaching a boiling point in doctors’ offices. “I hope this study is a wake-up call, and I hope it’s time to say ‘okay, what we are doing isn’t working,’ and start asking ‘what should we be doing?’” says Kempe.

Better Grocery Stores Alone Can’t Improve Kids’ Diets, Study Finds

Even if you build them, they won’t come, says the latest study on finding ways to get more healthy foods to young children

There’s been a lot of talk lately about food deserts and lack of access to healthy, nutritious food for many families living in rural and lower-income urban areas. So the solution seems to be to increase the availability of healthier fare, and what better way than to build a full service supermarket in the neighborhoods without one?

That’s what a government-sponsored program called Health Food Financing Initiative does, enticing supermarket chains to build stores in lower income areas with favorable tax credits. These stores are also required to meet some criteria meant to make the most of their presence in areas where fresh and nutritious foods are harder to come by. In New York, for example, the state program requires that at least 30% of a store’s floor space be devoted to perishable foods like produce and fruit, with at least 500 square feet dedicated specifically to fresh produce.

A new study published in journal Public Health Nutrition looked at whether the supermarkets are actually making a difference. Brian Elbel, associate professor of population health and health policy at New York University School of Medicine, and his colleagues compared eating habits in families in a part of the Bronx with a new supermarket and in a close by neighborhood without one.

To capture any change in the families’ food-buying habits over time, the researchers stopped parents on the street in these neighborhoods and asked them questions about their eating and food buying patterns, and then called the participants around six months later, and again a year after that first encounter.

The results were sobering. While there was an increase in those who said they shopped at the supermarket between the first and second rounds of questioning, that difference disappeared a year later. What the families were buying also didn’t change much, despite the supermarket selling fresh and healthy foods. At the start of the study 77% of those living in the neighborhood with the new supermarket said they had fresh fruits and vegetables in their homes, which dropped to 68% by the second follow up. The other neighborhood, however, showed a similar decline, from 78% to 65%.

In fact, both neighborhoods showed similar changes in food-buying trends, including positive ones such as a decrease in the availability of cookies, cakes, pastries and salty snacks in the home, so Elbel says it’s not possible to attribute them to the presence of the supermarket in the one community.

“It’s very clear that a supermarket alone does bring access to healthy food,” says Elbel. “But at the same time, does it bring unhealthy stuff, and introduce new products to the neighborhood that weren’t there before? Potentially.”

While healthy foods were available at the store, for example, they were not always the most affordable items, or the ones that the store promoted with special discounts or deals. Cost, it seems, overrules nutrition for many families making food-buying decisions.

While programs to increase the availability of full service food stores are laudable, Elbel says his results highlight the fact that access isn’t the only answer. “We can definitely imagine criteria that would make it more stringent for stores to qualify for these programs, and provide more detail on how the store is structured, what products are promoted or which products are available and how they are priced,” he says. “The question is, if we provide the tax credits and these constraints, will stores still be interested in opening in [food desert] neighborhoods? I don’t know.”

It’s also possible that the supermarket didn’t have the impact public health officials anticipated because the neighborhoods already had reasonable access — a train or bus ride away — to full service stores, before the new store opened. Almost 90% of the participants said they shopped at a supermarket, not convenience stores, for meals they made at home, so the new store likely didn’t do much to change that pattern. That suggests, says Elbel, that policy makers may also need stricter definitions of food deserts or areas that need nutritional attention.

“Just building a supermarket is not enough,” he says. “We need more data on what exactly a food desert is, and exactly where to place a supermarket. We have to look at access more broadly, and make clear that improving health is not just about access.” That’s a bigger challenge, but as the study shows, needs to be addressed if healthier fare is going to find its way onto more dinner plates.

The New Way To Prevent Nut Allergies?

It's with nuts

For years, the advice to parents worried about food allergies has focused, for reasons that make intuitive sense, on avoidance. After all, if kids don’t eat common allergens like peanuts, dairy or eggs, they can’t have a bad reaction to them.

How a Baby Was Born Encased in an Amniotic Sac

Cedars-Sinai Medical CenterSilas Johnson born still in the amniotic sac at the Neonatal Intensive Care Unit, part of the Maxine Dunitz Children's Health Center at Cedars-Sinai Medical Center on Dec. 6th, 2014 in Los Angeles.

The physician was so surprised that he snapped a photo on his phone

Correction appended

Silas Johnson is barely a day old and is already an internet sensation. The Los Angeles infant was born three months early, and was remarkably still completely encased in his amniotic sac, making it appear as if doctors delivered a large bubble with a tiny baby inside.

Johnson was born at Cedars-Sinai Medical Center via C-section, curled in the hallmark fetal position within, and his hands were visible pressing against the clear membrane of the sac. His physician was so surprised by the rare birth that he snapped a photo on his cell phone while his team rushed to ensure that the baby’s breathing and heart rate were normal.

The sac is the baby’s home during gestation, filling with fluid to cushion him during pregnancy. Just before birth, it normally ruptures — the so-called ‘water breaking’ that signals an expectant mom that labor is underway. (In cases where the water doesn’t break, doctors can puncture the sac to release the fluid.) In Cesarean sections like this one, doctors frequently pierce through the sac as they make their incision to remove the baby.

Cedars-Sinai Medical CenterSilas Johnson born still in the amniotic sac with mother Chelsea Philips at the Neonatal Intensive Care Unit, part of the Maxine Dunitz Children’s Health Center at Cedars-Sinai Medical Center on Dec. 6th, 2014 in Los Angeles.

In vaginal births, the sac remains in the mother as part of the placenta, and isn’t released until the placenta is removed in the afterbirth. But in some births, parts of the sac follow the baby through the birth canal.

While seemingly unusual, births ‘en caul,’ in which the infant remains entirely inside the sac during the journey through the birth canal, can be intentional, particularly when the baby is premature. Dr. Amos Grunebaum, director of obstetrics at NewYork-Presbyterian Weill Cornell Medical Center, purposefully delivers some of his babies in the sac, as a way to protect them during the delivery process. “It protects the baby from being injured; it serves as a cushion around the baby.”

Amniotic sacs and its fluid are connected to the placenta, which provides oxygen to the baby. So as soon as the baby is born, the sac must be ruptured to help the baby breathe.

“There are a lot of myths surrounding en caul births,” says Grunebaum. “There are many, many difference sources in the literature where people think the person delivered that way has certain powers.”Johnson’s mother Chelsea isn’t worried about that, but told CNN after seeing her doctor’s picture that “Silas, you’re a little special baby.”

Correction: This article originally misstated the baby’s last name. It is Johnson.

A Simple Skin Test May Detect Alzheimer’s

There’s new hope that the first signs of these brain disorders may lie in the skin

Detecting Alzheimer’s and Parkinson’s diseases as early as possible is critical. But while doctors know that the conditions can start 15 to 20 years before the symptoms appear, there aren’t many reliable ways of pinpointing exactly when that occurs. Now, scientists led by Dr. Ildefonso Rodriguez-Leyva at Central Hospital in University of San Luis Potosi in Mexico report that the skin may hold the clue to such early detection.

In a study that will be presented in April at the American Academy of Neurology’s annual meeting in Washington, D.C., Rodriguez-Leyva found that compared to healthy patients and those with age-related dementia, patients with Alzheimer’s and Parkinson’s diseases had seven times higher levels of an altered form of a protein called tau in skin biopsies, and Parkinson’s patients also showed seven to eight times greater levels of a harmful version of another protein known as alpha-synuclein. Researchers aren’t sure what alpha-synuclein’s role is in the brain, but in Parkinson’s patients, it tends to clump into harmful aggregates that interrupt normal nerve function. Tau is involved in the brain decline associated with Alzheimer’s; as nerve cells die, the normally aligned molecules of tau, which function like railroad tracks to transport nutrients, collapse, twisting into unorganized masses of tangled protein.

Rodriguez-Leyva turned to the skin to look for signs of the altered brain proteins since the skin and brain share a common embryonic origin; while everyone makes the two proteins, those who go on to develop Alzheimer’s or Parkinson’s seem to be especially vulnerable to having them fold in abnormal ways and stick together in damaging masses in the brain. If there were genetic signals dictating these sticky forms of the proteins, he speculated, then those signals might be detectable in the skin as well. “The ectoderm originates the nervous tissue and the skin,” he writes in an email to TIME discussing the study. “Our idea is that they have a similar program of protein expression. Therefore the skin could reflect events taking place in the nervous system.”

The study involved only a few dozen patients — 20 with Alzheimer’s, 16 Parkinson’s patients and 17 with age-related dementia, who were compared to 12 healthy controls — so more work needs to be done to confirm the findings. But the results hint that it may be possible to detect these neurodegenerative conditions sooner, and it also provides drug developers with more confidence that targeting abnormal forms of tau and alpha-synuclein may lead to effective treatments.

The Surprising Way to Treat Peanut Allergies

In a breakthrough study, researchers show that it’s not only possible to tamp down allergic reactions to peanuts, but by eating small amounts of them infants can avoid getting allergic in the first place

More studies hint that it’s possible to “train” the immune system to tolerate peanuts even if it doesn’t want to by giving children with peanut allergies small amounts of peanuts over a period of time. But researchers now report that it may be possible to prevent peanut allergies altogether. In a study published Monday in the New England Journal of Medicine, researchers led by Gideon Lack, a professor of pediatric allergy at King’s College London and Guy’s and St. Thomas’ Hospital, found that non-allergic young infants who ate small amounts of peanuts at an early age had a much lower rate of peanut allergy than those who avoided nuts altogether for five years.

“We are actually preventing the immune response from going along a pathway that leads to clinical reactivity, and it’s like, wow,” says Dr. Rebecca Gruchalla, professor of medicine and pediatrics at University of Texas Southwestern Medical Center who wrote an accompanying editorial. “It’s pretty cool to actually divert and keep the immune system from developing along a pathway that we don’t want it to go.”

Lack and his senior co-investigator George Du Toit, a pediatric allergy consultant at the College, conducted their study on 640 infants with severe eczema or egg allergy. These babies were chosen because of their increased risk of developing other food allergies, including to peanuts, and were enrolled when they were between four months and 11 months old. That’s an important window of opportunity, says Lack, to intervene and retrain the immune system to become tolerant to peanuts.

The group was divided into babies who showed a positive skin prick test to peanuts, and another who were negative. Each group was then randomly divided into those who were given to small amounts of peanuts to eat and those who were told to avoid it for five years. (Those with positive skin tests were given smaller amounts in gradually increasing doses if they could safely tolerate them, while those who were negative for peanut allergies were given larger doses.) Because the babies started out with varying levels of egg allergy and eczema, they also had differing levels of antibodies against peanuts; some had higher levels indicating they were already on the path toward developing allergic reactions to peanuts, even if they hadn’t tested positive and weren’t already allergic.

What’s noteworthy about the findings are that all groups that ate the peanuts, regardless of how far along they were toward developing peanut allergies, showed lower rates of peanut allergy when they were 5 compared to the babies who didn’t eat peanuts at all. The fact that even babies who were negative for peanut allergies at the start of the study, but who might go on to develop them, could prevent the allergy is a potentially game-changing idea.

“In primary prevention we can halt the process before the disease starts,” says Lack. “In secondary prevention, in the babies who already were positive for peanut allergy, the ball is already rolling downhill, but we can still prevent it, and push it back up the hill. We showed both primary prevention and secondary prevention were effective.” Overall, only 2% of the babies who ate peanuts were allergic to peanuts when they were 5, compared to nearly 14% of those who didn’t eat any peanuts during that time. For those who were already positive for peanut allergies at the start of the study, nearly 11% of those who ate small amounts of peanuts ended up getting a peanut allergy compared to 35% of those who avoided them.

It’s not clear how long the protection from peanut allergies lasts; other studies that used similar food exposure strategies in children with egg and milk allergies showed that as soon as the exposure to the allergy-causing food was stopped, the tolerance waned and the allergic reaction returned. Lack and his colleagues are continuing their study by asking all of the participants to avoid eating peanuts for one year and then giving them peanuts to see whether the peanut-consuming group remain non-allergic. “That will tell us whether we truly prevented peanut allergy in the long run or just put the brake on the development of peanut allergy,” he says.

Whether the approach will work on other food allergies, or even other allergies to cats, dogs or pollen, isn’t clear. Lack and his team have not, for example, fully analyzed the data on whether the peanuts helped the babies’ eczema or egg allergies to abate. But the results hint that the immune response may be redirected, at least for some allergens, toward a non-allergic response.

It also hints that the rise in peanut allergies, especially in the U.S., may be in part of our own making. For years, the American Academy of Pediatrics (AAP), for example, advised parents to avoid giving their babies peanuts in order to protect them from develop allergic reactions. Mothers-to-be were even advised to avoid eating peanuts during pregnancy to reduce their babies’ chances of becoming allergic. But recent studies in animals show that the immune system’s response to things like peanuts, egg, milk and other allergens may be a balance between exposure through the gut and exposure through the skin. Skin exposure tends to trigger aggressive immune responses that treat most new objects, including peanut protein, as foreign, and therefore sensitizes the body to recognize the food as foreign and dangerous. Eating such proteins, on the other hand, presents them in a different way to the immune system that recognizes their nutritious value. When these two routes are in balance, the gut-based system overrides the skin-based signals and the body sees peanuts as friend rather than foe.

But if babies aren’t eating peanuts, then the signals about peanut proteins entering via the skin become dominant, and nuts become an unwanted intruder rather than a welcome source of food. That’s why, for example, Lack and others believe that rates of peanut allergy are higher in countries like the U.S. where parents have been advised to avoid feeding their babies peanuts, compared to countries like Israel, where infants are given peanuts early on.

Based on recent findings, the AAP in 2008 changed its advice and now does not say parents should avoid feeding their babies peanuts. They haven’t concluded yet whether giving peanuts to infants early in life is a better choice, but given their latest data, Lack ,Du Toit and Gruchalla believe that it’s something that parents should discuss with their pediatricians and allergy specialists. We recommend that peanut be introduced very early on once weaning has been established,” says Du Toit. “Our study demonstrated that it’s safe as long as whole nuts are avoided for their choking hazard.” For children who come from families with no history of food allergies and whose parents or siblings don’t have other food allergies, peanuts can be started right away. For those who have a family history of food reactions, parents should consult with an allergist to get a skin prick test and then work with the specialist to determine the safest way to gradually introduce peanuts into their babies’ diet.

Such exposure to possible food allergens “is not part of clinical practice yet, but I think it will be likely that there are going to be experts who are going to get together and revise the guidelines to make it more common,” says Gruchalla. And hopefully lower rates of food allergies in coming years.

The latest studies reveal some surprising things about melanin, the compound responsible for tans, and the need for sunscreen after sun exposure

Now, in a series of experiments described in the journal Science, researchers say that may not be enough to shield against skin cancer. Working with human cells in a lab dish, as well as with mouse models, they found that melanin—which is produced in response to UV exposure to protect sensitive skin from being damaged—may have a dark side to its skin-protecting role. And, even more concerning, the harm triggered by the sun’s rays may linger long after the sun sets.

Douglas Brash, professor of therapeutic radiology and dermatology at Yale University School of Medicine, and his colleagues say that activating melanin has lasting effects—some positive, but mostly negative—on the body’s chemistry for up to three hours after sun exposure. That could mean that the risk of skin cancer from agents generated by UV damage continues even in the dark, they add.

Melanin is supposed to be the body’s natural sunblock. It’s released in response to UV light and protects delicate skin from burning, as well as the DNA deeper in skin cells from being scrambled so they don’t cause cancer. But when the scientists exposed mouse cells to UV light, they found that the melanin-containing cells produced mutations, and continued to do so for three hours after the light was removed. Similar cells from albino mice, which are missing melanin, didn’t show the same effect. Human melanin-containing cells also generated these damaging changes long after exposure.

The vast span of time during which damage could occur after exposure surprised the researchers. “To have the [changes] made after exposure is like having a process that should have taken a second during the time of the dinosaurs just finish up today,” says Brash. “That’s how bizarre this is.”

Once activated, he says, some of the melanin is highly energized, and in that state, starts to degrade. “When you create high-energy molecules, the energy has to go somewhere,” says Brash. In some cases, it transfers to the DNA where it continues to monkey with normal DNA codes for hours.

The good news is that this process can be interrupted, as long as the excess energy has an outlet. “If we can divert some of that energy to another molecule and change it into heat, it doesn’t cause problems,” says Brash. In the study, he experimented with some agents including vitamin E, which eliminated the harmful high-energy agents, and kojic acid, which reduced them by 85%.

But it’s not clear yet how these agents should be used or for how long after sun exposure. The findings do make a strong case, however, that applying sunscreen after being out in the sun might become just as important as slathering them on while outside. In the meantime, “continue doing what you’re doing and use sunscreen,” says Brash. “Sunscreens do block UV wavelengths, and will prevent some of these processes from starting. And the lower dose of exposure you have, the better off you are. We just might have to start considering continuing that protection a little longer than we thought.”

Even a Little Bit of Physical Activity Can Help the Heart

A little activity goes a long way, even for the elderly who may have mobility problems

Most exercise recommendations include several sessions of moderate to vigorous activity each week, but not all adults are physically up to the task.

There’s a lot of back and forth among experts on just how much activity people need to enjoy health benefits, and whether it’s the intensity of exercise or the amount that matters. That’s especially important for older people who are more likely to have issues with mobility but are also at higher risk of heart disease and other problems that physical activity can help. For them, is even a little more movement enough, or do they need to reach a certain threshold, which for many is unrealistic?

To find out, Thomas Buford, assistant professor of aging and geriatric research at the University of Florida College of Medicine, reports in the Journal of the American Heart Association on a study involving 1,170 older adults ages 74 to 84 who had some limits on their mobility. Each participant wore an accelerometer to record their daily amount of physical activity, and the scientists calculated each person’s risk of having heart events like heart attacks or stroke based on established risk factors like age, cholesterol, blood pressure and smoking status.

As expected, they found that those who were sedentary, or logged the least counts on their accelerometers, had the highest risk of having a heart event in the next 10 years. But to Buford’s surprise, the group that incorporated just a little bit more activity — such as moving around the house, doing chores and the like — showed lower risk than the sedentary group.

That’s encouraging, since it suggests that even a little more movement during the day can contribute to better health and lower risk of heart-related problems. “These are what we would consider really low-level activities, but they did seem to have an influence,” says Buford. “When you look at older adults, particularly those with mobility challenges, to give them a recommendation to do 30 minutes of walking three to four times a week when they have trouble getting to their mailbox can be daunting. Here we can say that even low-level activities can be helpful.”

Part of that benefit may be coming from the fact that if the people in the study were moving, that means they weren’t sitting. There’s growing evidence that sitting itself may have adverse effects on the heart and body independent of activity. Brain signals during sitting, for example, may influence the way the body burns energy. In the current study, Buford wasn’t able to determine if the benefits from the slightly more active seniors came from sitting less, but he plans to study that relationship in a follow-up study in which one group of people will be assigned an exercise regimen and the other will not.

Buford is reluctant to use the word exercise to describe the activity that seemed to benefit those who moved a little more in his study, since the mobility was really minimal and not structured in any way. But avoiding the E word might actually help motivate older adults to get up and move. “A lot of people may feel that it’s too late, or maybe too difficult to exercise, but even activities that are barely above being sedentary can help,” Buford says. “It’s never too late to incorporate these things, and we shouldn’t underestimate the potential health benefit that incorporating more light activity into the day might have.”